1. Technical Field
This disclosure is directed to integrated circuits, and more particularly, to testing integrated circuits having source synchronous interfaces.
2. Description of the Related Art
Testing of an integrated circuit (IC) may be conducted in various ways. One common way of conducting testing of an IC is through the use of scan testing. Circuitry to support scan testing may provide internal access to an IC. Scan circuitry may be implemented by forming chains of scannable elements. Data may be serially shifted through the scannable elements of the scan chain. This may allow for the input of test stimulus data, as well as the capture and shifting out of test result data. Using available scan circuitry, manufacturing tests may be conducted on ICs prior to their shipment to a customer in order to verify the circuitry therein.
One type of test that may be supported by scan testing is known as a transition test. In a transition test, data shifted into a scan chain may cause logical transitions of circuitry coupled thereto. Such testing may be used to determine the ability of circuitry to undergo transitions responsive to stimulus designed to cause such transitions. Both logic 0 to logic 1 and logic 1 to logic 0 transitions may be tested during a typical transition test.
Some ICs include source synchronous interfaces. Transition testing on such source synchronous interfaces may be performed by conducting separate and independent internal transition tests on each side of the interface.